Active energy ray curable laminate adhesive resin composition

Abstract

To provide a new active energy ray-curable laminate adhesive resin composition which is excellent in adhesiveness and heat resistance.SOLUTION: Polyester polyurethane (meth)acrylate (A-1) having a glass transition temperature of lower than 40°C and a (meth)acrylate monomer (B) having an isobornyl group and the number of (meth)acryloyl groups of 1 are mixed in a weight ratio (A-1) / (B) of 1.0 / 1.0 to 8.0 / 1.0. A blended amount of polyester polyurethane (meth)acrylate (A-2) having a glass transition temperature of 40°C or higher is preferably 0-75 pts.wt. with respect to 100 pts.wt. of the polyester polyurethane (meth)acrylate (A-1) having a glass transition temperature of lower than 40°C.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an active energy ray-curable laminate adhesive resin composition.

Background Art

[0002] Regarding an active energy ray-curable laminate adhesive resin composition that cures by irradiating active energy rays and exhibits desired adhesive performance, the inventions disclosed in Patent Documents 1 to 3 have been proposed.

[0003] In Patent Document 1, a polyester polyurethane (meth) acrylate obtained by reacting a polyester polyol, a polyisocyanate, and a hydroxy (meth) acrylate having 5 or more carbon atoms constitutes the basic skeleton of the adhesive resin composition. When components for imparting various performances to the adhesive, such as an acid anhydride, an epoxy resin having a number average molecular weight of less than 2000, a photo cationic initiator, a (meth) acrylate containing phosphoric acid, and a radical polymerizable compound containing an alkoxysilyl group, are blended, the basic performances required for an active energy ray-curable laminate adhesive are maintained, and an adhesive resin composition capable of imparting various performances is disclosed. However, there is no disclosure regarding (meth) acrylate monomers, nor is there any disclosure regarding the glass transition temperature.

[0004] In Patent Document 2, an invention regarding a UV-curable resin composition containing a UV-curable prepolymer, a UV-curable polyfunctional monomer, a photopolymerization initiator, and a silane coupling agent is disclosed. This UV-curable prepolymer can easily peel off a liquid crystal display from an adherend and rework it even at room temperature, and can impart good adhesiveness. As this UV-curable prepolymer, urethane (meth) acrylate is used, and as the UV-curable polyfunctional monomer, a (meth) acrylic monomer having two or more functional groups is shown to be used. However, UV-curable polyfunctional monomers, i.e., (meth)acrylic monomers having two or more functional groups, are formulated to enable rework of liquid crystal displays, and are added to increase the crosslinking density after curing and enhance viscoelasticity at room temperature. Furthermore, although the glass transition temperature of UV-curable prepolymers is preferably -10 to 20°C, monomers having isobornyl groups have not been studied and their properties are not disclosed.

[0005] Patent Document 3 discloses an invention relating to an active energy polymerizable resin composition comprising an α,β-unsaturated double bond group-containing compound and an active energy ray cationic polymerization initiator as essential components. The α,β-unsaturated double bond group-containing compound disclosed includes (meth)acrylates having one or more hydroxyl groups in the molecule, such as 2-hydroxyethyl acrylate and 4-hydroxybutyl acrylate, as essential components. However, regarding polyester polyurethane (meth)acrylate, its use is not excluded, but it is not considered an essential component. Furthermore, the glass transition temperature is only specified as a desirable range for the entire resin composition. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2015-13935 [Patent Document 2] Japanese Patent Publication No. 2018-24785 [Patent Document 3] Japanese Patent Publication No. 2015-174867 [Overview of the project] [Problems that the invention aims to solve]

[0007] The present invention aims to provide a novel active energy ray-curable laminate adhesive resin composition that hardens upon irradiation with active energy rays, exhibits high adhesion to metals and plastic films, and has excellent heat resistance. [Means for solving the problem]

[0008] The inventors of the present invention have discovered that by blending a polyester polyurethane (meth)acrylate (A-1) with specific conditions and a (meth)acrylate monomer (B) with specific conditions, it is possible to obtain a resin composition that can achieve both the adhesiveness and heat resistance required for active energy ray curable laminate adhesives, and have completed the present invention. In the present invention, the polyester polyurethane (meth)acrylate (A-1) has a glass transition temperature of less than 40°C. Furthermore, the (meth)acrylate monomer (B) has an isobornyl group and has one (meth)acryloyl group. Then, the polyester polyurethane (meth)acrylate (A-1) and the (meth)acrylate monomer (B) are mixed in a weight ratio of (A-1) / (B) = 1.0 / 1.0 to 8.0 / 1.0. Polyisocyanates or isocyanate compounds having radically polymerizable unsaturated bonds that are not components of the aforementioned polyester polyurethane (meth)acrylate (A-1) shall not be included in amounts of 20% by weight or more. In other words, they shall not be included at all, or if included, the amount shall be less than 20% by weight.

[0009] In carrying out the present invention, the polyester polyurethane (meth)acrylate may or may not contain any material having a glass transition temperature of 40°C or higher. In other words, it is preferable that the amount of polyester polyurethane (meth)acrylate (A-2) having a glass transition temperature of 40°C or higher is 0 to 75 parts by weight per 100 parts by weight of the polyester polyurethane (meth)acrylate (A-1) having a glass transition temperature of less than 40°C.

[0010] Furthermore, in carrying out the present invention, desired properties can be imparted to the active energy ray curable laminate adhesive resin composition by incorporating at least one of the following: epoxy resin (C), alkoxysilyl group-containing radical polymerizable compound (D), phosphate group-containing (meth)acrylate (E), and photocationic polymerization initiator (F). The appropriate amounts to be incorporated are 1 to 10% by weight for epoxy resin (C), 0.1 to 5% by weight for alkoxysilyl group-containing radical polymerizable compound (D), 0.1 to 5% by weight for phosphate group-containing (meth)acrylate (E), and 0.1 to 5% by weight for photocationic polymerization initiator (F). [Effects of the Invention]

[0011] The present invention provides a novel resin composition that can achieve both the adhesive properties and heat resistance required for active energy ray-curable laminate adhesives. Furthermore, the present invention can provide an active energy ray curable laminate adhesive resin composition that can exhibit desired properties. [Modes for carrying out the invention]

[0012] Embodiments of the present invention will be described below.

[0013] The active energy ray curable laminate adhesive resin composition according to the present invention is a mixture of polyester polyurethane (meth)acrylate (A-1) having a glass transition temperature of less than 40°C and (meth)acrylate monomer (B) under predetermined conditions, and can be carried out by optionally adding polyester polyurethane (meth)acrylate (A-2) having a glass transition temperature of 40°C or higher.

[0014] The number of (meth)acryloyl functional groups in the molecules of the polyester polyurethane (meth)acrylate (A-1) and polyester polyurethane (meth)acrylate (A-2) is not particularly limited, but from the viewpoint of adhesion between substrates, it is preferable to have two or more, and more preferably two to four. If there are fewer than two (meth)acryloyl groups, the crosslinking density after curing is low, resulting in weaker adhesion and heat resistance, and reduced practicality. If the number of (meth)acryloyl functional groups exceeds four, the crosslinking density is high, resulting in weaker adhesion.

[0015] The number-average molecular weight of polyester polyurethane (meth)acrylate (A-1) and polyester polyurethane (meth)acrylate (A-2) is not particularly limited, but is preferably in the range of 4,000 to 30,000. If the number-average molecular weight is less than 4,000, the molecular weight between crosslinking points is low, which impairs flexibility and weakens adhesion. If the number-average molecular weight exceeds 30,000, the viscosity is high, which reduces coating suitability and makes it impractical. Also, because the molecular weight between crosslinking points is high, it becomes too soft after curing, resulting in weak adhesion. The number-average molecular weight in this invention was measured by gel permeation chromatography (GPC).

[0016] Polyester polyurethane (meth)acrylate (A-1) and polyester polyurethane (meth)acrylate (A-2) can be obtained by reacting the polyol component polyester polyol (a-1) with an isocyanate compound (a-2) and hydroxy(meth)acrylate (a-3).

[0017] The polyester polyol (a-1) is obtained by subjecting, for example, a polybasic acid component such as isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, phthalic anhydride, succinic acid, adipic acid, azelaic acid, sebacic acid, maleic acid, fumaric acid, itaconic acid, and acid anhydrides thereof, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, tetrabromophthalic anhydride, tetrachlorophthalic anhydride, het acid anhydride, hymic acid anhydride, etc., alone or as a mixture, and a polyhydric alcohol component such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, triethylene glycol, tripropylene glycol, tetramethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, 1,3-butylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, hydrogenated bisphenol A, glycerin, trimethylolethane, trimethylolpropane, tris(hydroxymethyl)aminomethane, pentaerythritol, polyether polyol, polycarbonate polyol, acrylic polyol, polyurethane polyol, etc., alone or as a mixture, to dehydration condensation.

[0018] As the polyol component, a polyol other than the polyester polyol (a-1) can also be used in combination. For example, low molecular weight polyols such as 1,6-hexanediol and trimethylolpropane, and polyether polyol, acrylic polyol, and polyurethane polyol can be mentioned, and these can be used alone or in combination of two or more.

[0019] Examples of the isocyanate compound (a-2) include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, 1,5-naphthalene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 3,3'-dimethylphenylene diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), and 2,2,4-trimethylhexa Examples include methylene diisocyanate and norbornene diisocyanate. Furthermore, polyfunctional polyisocyanate compounds include their biuret, nurate, and trimethylolpropane adduct forms. Examples of isocyanate compounds having a (meth)acryloyl group include 2-isocyanatoethyl (meth)acrylate, 2-(2-methacryloyloxyethyl oxy)ethyl isocyanate, and 1,1-(bisacryloyloxymethyl)ethyl isocyanate, which can be used alone or in combination of two or more.

[0020] Examples of the hydroxy(meth)acrylate (a-3) include, as a compound having one (meth)acryloyl group, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 1,5-pentanediol mono(meth)acrylate, 1,6-hexanediol mono(meth)acrylate, cyclohexanedimethanol mono(meth)acrylate, polyether-modified hydroxyethyl (meth)acrylate, caprolactone-modified hydroxyethyl (meth)acrylate, etc.; and as a compound having two or more acryloyl groups, trimethylolpropane di(meth)acrylate, trimethylolethane di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol di(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, 2-hydroxy-3 acryloyloxypropyl (meth)acrylate, etc. These can be used alone or in combination of two or more. Also, considering the reaction rate during synthesis, a compound having a primary hydroxyl group is preferred, and among them, 2-hydroxyethyl (meth)acrylate is particularly preferred.

[0021] The synthesis of the polyester polyurethane (meth)acrylate (A-1) and the polyester polyurethane (meth)acrylate (A-2) can be carried out in a solvent as necessary. Examples of these solvents include hydrocarbons other than alcohols, acetate esters, ketones, etc., and from the viewpoint of coating workability, ethyl acetate or methyl ethyl ketone is preferred. Furthermore, known reaction accelerators can be used, including metal catalysts such as dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, and dibutyltin dimalate, as well as tertiary amines such as 1,8-diazabicyclo(5,4,0)undecene-7 and 1,5-diazabicyclo(4,3,0)-nonene-5, and reactive tertiary amines such as triethanolamine.

[0022] By using (meth)acrylate monomer (B), heat resistance can be imparted. However, if the number of (meth)acryloyl groups exceeds 1, the crosslinking density of the cured product increases, leading to increased curing shrinkage and thus weakening the adhesive properties.

[0023] An example of a (meth)acrylate monomer (B) is isobornyl (meth)acrylate.

[0024] By mixing polyester polyurethane (meth)acrylate (A-1) and (meth)acrylate monomer (B) in a weight ratio of 1.0 / 1.0 to 8.0 / 1.0, an adhesive resin composition with excellent adhesion and heat resistance is obtained. If (A-1) / (B) = less than 1.0 / 1.0, the flexibility of the cured material decreases, and the adhesive properties weaken. If (A-1) / (B) = greater than 8.0 / 1.0, the cured material becomes too soft, and its heat resistance weakens.

[0025] In addition to polyester polyurethane (meth)acrylate (A-1) with a glass transition temperature of less than 40°C, using polyester polyurethane (meth)acrylate (A-2) with a glass transition temperature of 40°C or higher can impart heat resistance. However, if the amount exceeds 75% by weight relative to polyester polyurethane (meth)acrylate (A-1), the flexibility of the cured product decreases and the adhesive properties weaken.

[0026] In carrying out the present invention, desired properties can be imparted to an active energy ray-curable laminate adhesive resin composition by incorporating at least one of the following: epoxy resin (C), alkoxysilyl group-containing radical polymerizable compound (D), phosphate group-containing (meth)acrylate (E), and photocationic polymerization initiator (F).

[0027] The epoxy resin (C) of the present invention is a general term for resins having epoxy groups in their molecules and epoxy (meth)acrylates obtained by modifying resins having epoxy groups in their molecules and adding (meth)acryloyl groups to them. The epoxy resin (C) is preferably one with excellent heat resistance, and examples include bisphenol A type epoxy resin, bisphenol F type epoxy resin, alicyclic epoxy resin, novolac type epoxy resin, and epoxy acrylate. For example, bisphenol A type epoxy resins include those manufactured by Mitsubishi Chemical Corporation (jER825, jER827, jER828, jER1001, jER1002, jER1003, jER1004, jER1032H60), bisphenol F type epoxy resins include those manufactured by Mitsubishi Chemical Corporation (jER4004P, jER4005P), alicyclic epoxy resins include those manufactured by Daicel Corporation (Celoxide 2021P, Celoxide 2081, Epolid GT401), novolac type epoxy resins include those manufactured by DIC Corporation (EPICLON N-660, EPICLON N-740), and epoxy acrylates include those manufactured by Daicel-Ornex Corporation (EBECRYL600, EBECRYL3603, EBECRYL3700). These can be used individually or in combination of two or more types. The preferred mixing ratio is 0.1 to 10% by weight. Adding more than 10% by weight will weaken the adhesive properties.

[0028] Alkoxysilyl group-containing radical polymerizable compounds (D) are effective in improving adhesion to metallic materials such as metal foils. The radical polymerizable compounds are not particularly limited as long as they have an alkoxysilyl group in their molecule. Examples include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, allyltrimethoxysilane, 3-(meth)acryloxypropyltrimethoxysilane, 3-(meth)acryloxypropyltriethoxysilane, p-styryltrimethoxysilane, p-styryltrimethoxysilane, and organosiloxanes obtained by condensing these individually or in combination of two or more. These can be used individually or in combination of two or more. A blending ratio of 0.1 to 5% by weight is preferable. Blending at 5% by weight or more will weaken the adhesive properties and heat resistance.

[0029] The phosphate group-containing (meth)acrylate (E) of the present invention is particularly effective in improving adhesion to metallic materials such as metal foils. A blending ratio of 0.1 to 5% by weight is preferable. Blending at 5% by weight or more will weaken the adhesive properties and heat resistance. While phosphorus compounds that do not contain (meth)acryloyl groups can be used alone or in combination, (meth)acrylate (E) containing phosphate groups, which are involved in the crosslinking reaction, is more preferable because it provides superior adhesion and durability. Examples of phosphate-containing (meth)acrylates (E) include 2-(meth)acryloyloxyethyl acid phosphate and bis(2-(meth)acryloyloxyethyl)-acid phosphate. Examples include those manufactured by Kyoeisha Chemical Co., Ltd. (Light Ester P-1M, Light Ester P-2M, Light Acrylate P-1A) and BASF (Laromer PA9083), which can be used alone or in combination of two or more.

[0030] The photocationic polymerization initiator (F) is used as a cationic polymerization initiator for the epoxy resin (C) and the alkoxysilyl group-containing radical polymerizable compound (D). It is an onium salt, such as an ionic aromatic sulfonium salt or aromatic iodonium salt, consisting of a cationic and anionic moiety. Examples include those manufactured by IGM Resins BV (Omnicat 250, Omnicat 270), ADEKA Corporation (ADEKA Optomer SP series), and Sunapro Co., Ltd. (CPI-100P, CPI-101A). From the viewpoint of reactivity, a blending ratio of 0.1 to 5% by weight is preferred.

[0031] The adhesive resin composition of the present invention may, if necessary, contain polyisocyanates or isocyanate compounds having radically polymerizable unsaturated bonds, to the extent that it does not impair the requirement for short aging. The reaction between the hydroxyl groups in the cured adhesive and the moisture in the substrate and the isocyanate groups increases the cohesive force, thereby improving the adhesive strength. In terms of the amount added, adding more than 20% by weight can significantly impair the short-aging process, or the isocyanate may react with water such as moisture to generate carbon dioxide, which can cause bubbles in the adhesive layer. Therefore, it is preferable to add less than 20% by weight.

[0032] The adhesive resin composition of the present invention may, as needed, contain coloring pigments, extender pigments, tackifiers, dispersants, defoamers, wetting agents, antistatic agents, thickeners, antioxidants, UV absorbers, radical scavengers, etc., to the extent that it does not impair the performance.

[0033] The adhesive resin composition of the present invention hardens instantaneously upon irradiation with active energy rays; however, a photoradical polymerization initiator may be added to improve the curability. Examples of photoradical polymerization initiators include benzophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexylphenyl-ketone, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methylpropan-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropionyl)-benzyl]-phenyl}-2-methylpropan-1-one, phenylglyoxylic acid methyl ester, and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan- Examples include 1-one, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, 1,2-octanedione, ethanone, and 1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-,1-(O-acetyloxime), which can be used alone or in combination of two or more.

[0034] The adhesive resin composition of the present invention can be diluted with solvents such as hydrocarbons, acetate esters, ketones, and alcohols to adjust its viscosity according to the coating method and specifications of the coating machine. From the viewpoint of coating workability, ethyl acetate or methyl ethyl ketone is preferred.

[0035] The adhesive resin composition of the present invention can be diluted with a reactive diluent having radical polymerization properties to adjust its viscosity, in accordance with the coating method and specifications of the coating machine, to the extent that it does not impair the performance. Reactive diluents include monofunctional (meth)acrylates such as 4-t-butylcyclohexyl (meth)acrylate, 2-(2-ethoxyethoxy)ethyl (meth)acrylate, stearyl (meth)acrylate, diethylene glycol monobutyl ether (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, lauryl (meth)acrylate, isooctyl (meth)acrylate, tridecyl (meth)acrylate, isobornyl (meth)acrylate, myristyl (meth)acrylate, and 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate. Examples include difunctional (meth)acrylates such as acrylate, ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, and tripropylene glycol di(meth)acrylate, as well as polyfunctional (meth)acrylates such as trimethylolpropane tri(meth)acrylate, ethoxylated (3) trimethylolpropane tri(meth)acrylate, and propoxylated (3) glyceryl tri(meth)acrylate, which can be used alone or in combination of two or more.

[0036] The adhesive resin composition of the present invention can be laminated using conventional methods. For example, when diluted with a solvent, it is coated onto a film using a dry lamination method, and after drying, another film is bonded to it, and then cured by irradiation with activated energy rays. The application rate is 1 to 10 g / m² in dry state. 2 While this range is common, it should be determined according to the type of film and the required performance.

[0037] There are no particular limitations on the laminating films, and examples include plastic films such as polyethylene terephthalate, nylon, polyethylene, and polypropylene, barrier films with vapor-deposited aluminum, silica, and alumina, and metal foils such as aluminum foil, copper foil, and stainless steel foil. These can be used to bond various films together. In particular, metal foils such as aluminum foil, copper foil, and stainless steel foil can be used as exterior materials for energy storage devices, and this adhesive can be suitably used to laminate and bond them with other films. [Examples]

[0038] The present invention will be described in more detail by the following examples and comparative examples, but the present invention is not limited to these examples.

[0039] <Example of synthesis of polyester polyurethane acrylate (A)-[I]> In a flask equipped with a nitrogen inlet tube, stirrer, rectification column, and condenser, neopentyl glycol (130 g), 1,6-hexanediol (180 g), ethylene glycol (80 g), isophthalic acid (310 g), and terephthalic acid (300 g) were added. Dehydration condensation was carried out at an internal temperature of 180-200°C while stirring, and after confirming that the resin acid value reached 15 mg KOH / g, the dehydration reaction was further carried out at 200-240°C while nitrogen bubbling was performed. After confirming that the resin acid value was 2 mg KOH / g or less, the internal pressure was reduced to 15 Torr and the reaction continued, and after confirming that the resin acid value was 0.1 mg KOH / g or less, a polyester polyol with a number average molecular weight of 5800 and a hydroxyl value of 19.3 mg KOH / g was obtained. The obtained polyester polyol was cooled to 20°C, and dibutyltin dilaurate (0.2 g) and tolylene diisocyanate (38.5 g) were added. The mixture was reacted under a nitrogen atmosphere at 80-85°C for 6 hours to obtain a urethane prepolymer having isocyanate groups at both ends. 20.0 g of 2-hydroxyethyl acrylate was added to the obtained urethane prepolymer, and the reaction was carried out at 80-85°C. After the reaction had progressed, the synthesis was terminated by confirming that the absorption of the isocyanate group had completely disappeared using infrared absorption spectroscopy. Polyester polyurethane acrylate (A)-[I] with a number average molecular weight of 6000 and a glass transition temperature of 50°C was obtained.

[0040] <Example of synthesis of polyester polyurethane acrylate (A)-[II]> In a flask equipped with a nitrogen inlet tube, stirrer, rectification column, and condenser, neopentyl glycol (130 g), 1,6-hexanediol (140 g), ethylene glycol (110 g), isophthalic acid (310 g), and terephthalic acid (310 g) were added. Dehydration condensation was carried out at an internal temperature of 180-200°C while stirring, and after confirming that the resin acid value reached 15 mg KOH / g, the dehydration reaction was further carried out at 200-240°C while nitrogen bubbling was performed. After confirming that the resin acid value was 2 mg KOH / g or less, the internal pressure was reduced to 15 Torr and the reaction continued, and after confirming that the resin acid value was 0.1 mg KOH / g or less, a polyester polyol with a number average molecular weight of 6100 and a hydroxyl value of 18.4 mg KOH / g was obtained. The obtained polyester polyol was cooled to 20°C, and dibutyltin dilaurate (0.2 g) and tolylene diisocyanate (36.6 g) were added. The mixture was reacted under a nitrogen atmosphere at 80-85°C for 6 hours to obtain a urethane prepolymer having isocyanate groups at both ends. 11.5 g of 2-hydroxyethyl acrylate was added to the obtained urethane prepolymer, and the reaction was carried out at 80-85°C. After the reaction had progressed, the synthesis was terminated by confirming that the absorption of the isocyanate group had completely disappeared using infrared absorption spectroscopy. Polyester polyurethane acrylate (A)-[II] with a number average molecular weight of 9000 and a glass transition temperature of 63°C was obtained.

[0041] <Example of synthesis of polyester polyurethane acrylate (A)-[III]> In a flask equipped with a nitrogen inlet tube, stirrer, rectification column, and condenser, neopentyl glycol (120 g), 1,6-hexanediol (234 g), ethylene glycol (47 g), isophthalic acid (400 g), adipic acid (179 g), and sebacic acid (20 g) were added. Dehydration condensation was carried out at an internal temperature of 180-200°C while stirring, and after confirming that the resin acid value reached 15 mg KOH / g, the dehydration reaction was further carried out at 200-240°C while nitrogen bubbling was performed. After confirming that the resin acid value was 2 mg KOH / g or less, the internal pressure was reduced to 15 Torr and the reaction continued, and after confirming that the resin acid value was 0.1 mg KOH / g or less, a polyester polyol with a number average molecular weight of 4400 and a hydroxyl value of 25.5 mg KOH / g was obtained. The obtained polyester polyol was cooled to 20°C, and dibutyltin dilaurate (0.2 g) and tolylene diisocyanate (61.5 g) were added. The mixture was reacted under a nitrogen atmosphere at 80-85°C for 6 hours to obtain a urethane prepolymer having isocyanate groups at both ends. 35.9 g of 2-hydroxyethyl acrylate was added to the obtained urethane prepolymer, and the reaction was carried out at 80-85°C. After the reaction had progressed, the synthesis was terminated after confirming that the absorption of the isocyanate group had completely disappeared by infrared absorption spectroscopy. Polyester polyurethane acrylate (A)-[III] with a number average molecular weight of 8000 and a glass transition temperature of -20°C was obtained.

[0042] <Example of synthesis of polyester polyurethane acrylate (A)-[IV]> In a flask equipped with a nitrogen inlet tube, stirrer, rectification column, and condenser, neopentyl glycol (190g), 1,6-hexanediol (200g), ethylene glycol (50g), isophthalic acid (420g), adipic acid (20g), and sebacic acid (100g) were added. Dehydration condensation was carried out at an internal temperature of 180-200°C while stirring, and after confirming that the resin acid value reached 15 mgKOH / g, the dehydration reaction was further carried out at 200-240°C while nitrogen bubbling was performed. After confirming that the resin acid value was 2 mgKOH / g or less, the internal pressure was reduced to 15 Torr and the reaction continued, and after confirming that the resin acid value was 0.1 mgKOH / g or less, a polyester polyol with a number average molecular weight of 4100 and a hydroxyl value of 27.4 mgKOH / g was obtained. The obtained polyester polyol was cooled to 20°C, and dibutyltin dilaurate (0.2 g) and tolylene diisocyanate (55.4 g) were added. The mixture was reacted under a nitrogen atmosphere at 80-85°C for 6 hours to obtain a urethane prepolymer having isocyanate groups at both ends. 30.8 g of 2-hydroxyethyl acrylate was added to the obtained urethane prepolymer, and the reaction was carried out at 80-85°C. After the reaction had progressed, the synthesis was terminated after confirming that the absorption of the isocyanate group had completely disappeared by infrared absorption spectroscopy. Polyester polyurethane acrylate (A)-[IV] with a number average molecular weight of 15,000 and a glass transition temperature of -10°C was obtained.

[0043] <Example of synthesis of polyester polyurethane acrylate (A)-[V]> In a flask equipped with a nitrogen inlet tube, stirrer, rectification column, and condenser, neopentyl glycol (200 g), 1,6-hexanediol (150 g), ethylene glycol (60 g), isophthalic acid (440 g), and adipic acid (150 g) were added. Dehydration condensation was carried out at an internal temperature of 180-200°C while stirring, and after confirming that the resin acid value reached 15 mg KOH / g, the dehydration reaction was further carried out at 200-240°C while nitrogen bubbling was performed. After confirming that the resin acid value was 2 mg KOH / g or less, the internal pressure was reduced to 15 Torr and the reaction continued, and after confirming that the resin acid value was 0.1 mg KOH / g or less, a polyester polyol with a number average molecular weight of 6000 and a hydroxyl value of 18.7 mg KOH / g was obtained. The obtained polyester polyol was cooled to 20°C, and dibutyltin dilaurate (0.2 g) and tolylene diisocyanate (20.5 g) were added. The mixture was reacted under a nitrogen atmosphere at 80-85°C for 6 hours to obtain a urethane prepolymer having isocyanate groups at both ends. 17.9 g of 2-hydroxyethyl acrylate was added to the obtained urethane prepolymer, and the reaction was carried out at 80-85°C. After the reaction had progressed, the synthesis was terminated by confirming that the absorption of the isocyanate group had completely disappeared using infrared absorption spectroscopy. Polyester polyurethane acrylate (A)-[V] with a number average molecular weight of 8400 and a glass transition temperature of 20°C was obtained.

[0044] <Example of synthesis of polyester polyurethane acrylate (A)-[VI]> In a flask equipped with a nitrogen inlet tube, stirrer, rectification column, and condenser, neopentyl glycol (150 g), 1,6-hexanediol (200 g), ethylene glycol (50 g), isophthalic acid (250 g), adipic acid (100 g), and sebacic acid (250 g) were added. Dehydration condensation was carried out at an internal temperature of 180-200°C while stirring, and after confirming that the resin acid value was 15 mg KOH / g, the dehydration reaction was further carried out at 200-240°C while nitrogen bubbling was performed. After confirming that the resin acid value was 2 mg KOH / g or less, the internal pressure was reduced to 15 Torr and the reaction continued, and after confirming that the resin acid value was 0.1 mg KOH / g or less, a polyester polyol with a number average molecular weight of 3000 and a hydroxyl value of 37.0 mg KOH / g was obtained. The obtained polyester polyol was cooled to 20°C, and dibutyltin dilaurate (0.2 g) and tolylene diisocyanate (80.0 g) were added. The mixture was reacted under a nitrogen atmosphere at 80-85°C for 6 hours to obtain a urethane prepolymer having isocyanate groups at both ends. 45.2 g of 2-hydroxyethyl acrylate was added to the obtained urethane prepolymer, and the reaction was carried out at 80-85°C. After the reaction had progressed, the synthesis was terminated by confirming that the absorption of the isocyanate group had completely disappeared using infrared absorption spectroscopy. Polyester polyurethane acrylate (A)-[VI] with a number average molecular weight of 6600 and a glass transition temperature of -40°C was obtained.

[0045] <Glass transition temperature> The glass transition temperatures of these materials are shown in Table 1. (A)-[I] with a glass transition temperature of 50°C and (A)-[II] with a glass transition temperature of 63°C belong to the polyester polyurethane (meth)acrylate (A-2) category, which has a glass transition temperature of 40°C or higher. (A)-[III] with a glass transition temperature of -20°C, (A)-[IV] with a glass transition temperature of -10°C, (A)-[V] with a glass transition temperature of 20°C, and (A)-[VI] with a glass transition temperature of -40°C belong to the polyester polyurethane (meth)acrylate (A-1) category, which has a glass transition temperature of less than 40°C. In this invention, the glass transition temperature is the peak temperature of the logarithmic decay rate measured using a rigid pendulum type physical property tester (RPT-3000W, manufactured by A&D Co., Ltd.). For example, a coating film with a dry thickness of 20 μm was prepared, and the heating rate was 3°C / min using a cylinder edge.

[0046] <Preparation of adhesive resin compositions according to the examples and comparative examples> The polyester polyurethane acrylate (A)-[I]~(A)-[VI] obtained above and other components were blended according to the blending ratios shown in Table 1 to prepare an active energy ray curable laminate adhesive resin composition. All blending ratios listed in Table 1 are by weight. The test results described later are also shown in Table 1. In addition, the blending ratio of polyester polyurethane (meth)acrylate (A-1) with a glass transition temperature of less than 40°C to (meth)acrylate monomer (B), and the blending ratio of polyester polyurethane (meth)acrylate (A-2) with a glass transition temperature of 40°C or higher to 100 parts by weight of polyester polyurethane (meth)acrylate (A-1) with a glass transition temperature of less than 40°C are also listed.

[0047] [Table 1]

[0048] According to the blending ratios shown in Table 1 above, polyester polyurethane (meth)acrylate (A-1), polyester polyurethane (meth)acrylate (A-2) as needed, (meth)acrylate monomer (B), epoxy resin (C), alkoxysilyl group-containing radical polymerizable compound (D), phosphate group-containing (meth)acrylate (E), photocationic polymerization initiator (F), and monomers (M) added as needed were blended.

[0049] For the (meth)acrylate monomer (B), either Light Ester IB-X (isobornyl methacrylate, homopolymer glass transition temperature = 180°C, manufactured by Kyoeisha Chemical Co., Ltd.) or Light Acrylate IB-XA (isobornyl acrylate, homopolymer glass transition temperature = 94°C, manufactured by Kyoeisha Chemical Co., Ltd.) was used. For epoxy resin (C), jER1032H60 (epoxy resin, manufactured by Mitsubishi Chemical Corporation) was used. For the alkoxysilyl group-containing radical polymerizable compound (D), X-40-9296 (manufactured by Shin-Etsu Chemical Co., Ltd.) was used. For the phosphate-containing (meth)acrylate (E), we used Light Ester P-2M (2-methacryloyloxyethyl acid phosphate, manufactured by Kyoeisha Chemical Co., Ltd.). Omnicat 250 (manufactured by IGM Resins BV) was used as the photocationic polymerization initiator (F). Of the monomers (M), NK ester DCP (tricyclodecane dimethanol dimethacrylate, homopolymer glass transition temperature = 190°C, manufactured by Shin Nakamura Chemical Industry Co., Ltd.) is a component other than (meth)acrylate monomer (B), but contributes to improved heat resistance as a polyfunctional methacrylate. On the other hand, light ester THF (tetrahydrofurfuryl methacrylate, homopolymer glass transition temperature = 60°C, manufactured by Kyoeisha Chemical Co., Ltd.) is a component not included in (meth)acrylate monomer (B), and was only included in the comparative example, but a decrease in heat resistance was observed when it was included. In addition, Omnirad184 (manufactured by IGM Resins BV) was used as a photoradical polymerization initiator in the examples and comparative examples. The proportions of each component are shown in Table 1. Note that the units for each substance in the proportions listed in Table 1 are parts by weight.

[0050] <Making Laminating Film> The adhesives for Examples 1-7 and Comparative Examples 1-4 shown in Table 1 were prepared with ethyl acetate to a solid content of 25%, and then coated by bar coating with a dry coating amount of 4.5 g / m². 2A 35μm aluminum foil (hereinafter referred to as ALM) was coated with the ethyl acetate, and after the ethyl acetate was evaporated using a dryer, a biaxially oriented nylon film (hereinafter referred to as ONY) [Bonyl-RX 15μm: manufactured by Kojin Film & Chemicals Co., Ltd.] was laminated to it. Furthermore, the ALM on the back side was also coated with a similar dry coating amount of 4.5g / m². 2 The film was coated in this manner, the ethyl acetate was evaporated with a dryer, and then an unstretched polypropylene film (hereinafter referred to as CPP) [Aromer Film ET20 40μm: manufactured by Okamoto Co., Ltd.] was laminated onto it and nipped on a hot plate at 60°C. Subsequently, after irradiating the ONY surface with active energy rays, the CPP surface was also irradiated with active energy rays to obtain a laminate film.

[0051] <test> The laminate films obtained using the adhesives of Examples 1-7 and Comparative Examples 1-4 were tested for adhesion and heat resistance, and the results are shown in Table 1. <Adhesiveness> Laminate film was cut into 15mm widths, and the T-shaped peel strength was measured at a tensile speed of 50mm / min using a tensile testing machine (EZ Test, manufactured by Shimadzu Corporation). The following evaluations were then performed for each. ○: 4N or higher, Pass ×: Less than 4N - Fail <Heat resistance> Laminate film was cut to a width of 55 mm, and a hemispherical rod was extruded 10.5 mm from the ONY side towards the CPP side using a cupping test machine. The processed convex portion was then extruded another 10.5 mm from the CPP side towards the ONY side. The processed laminate film was subjected to a heat resistance test at 200°C for 1 minute, and the following evaluations were made for each. ○: Not delaminated ×: Delamination

[0052] The results in Table 1 confirm that the active energy ray-curable laminate adhesives used in Examples 1 to 7 exhibited excellent adhesion and heat resistance. Comparative Example 1 did not contain component (B), and therefore did not achieve sufficient heat resistance. Comparative Example 2 did not achieve sufficient adhesion and heat resistance because (A-1) / (B) = less than 1.0 / 1.0. Comparative Example 3 did not achieve sufficient heat resistance because (A-1) / (B) = greater than 8.0 / 1.0, and Comparative Example 4 did not achieve sufficient adhesion and heat resistance because (A-1) / (B) = greater than 8.0 / 1.0 and (A-2) relative to (A-1) was greater than 75% by weight.

Claims

1. An active energy ray curable laminate adhesive resin composition containing polyester polyurethane (meth)acrylate (A-1) and (A-2), and (meth)acrylate monomer (B), The aforementioned polyester polyurethane (meth)acrylate (A-1) has a glass transition temperature of less than 40°C. The aforementioned polyester polyurethane (meth)acrylate (A-2) has a glass transition temperature of 40°C or higher. The (meth)acrylate monomer (B) has an isobornyl group and has 1 (meth)acryloyl group. The polyester polyurethane (meth)acrylate (A-1) and the (meth)acrylate monomer (B) are mixed in a weight ratio of (A-1) / (B) = 1.0 / 1.0 to 8.0 / 1.

0. Furthermore, the following (condition 1) must be met: Y / (X+Y+Z) is between 0.059 and 0.308 (Condition 1) (Here, X, Y, and Z are the weight ratios of each component to the sum of the three components (polyester polyurethane (meth)acrylate (A-1), polyester polyurethane (meth)acrylate (A-2), and (meth)acrylate monomer (B)), respectively, and are values ​​greater than 0 and less than 1.) In the adhesive resin composition excluding the diluent, The three components, polyester polyurethane (meth)acrylate (A-1), polyester polyurethane (meth)acrylate (A-2), and (meth)acrylate monomer (B), are blended in a total amount of 20% by weight or more, An active energy ray-curable laminate adhesive resin composition characterized in that it does not contain 20% by weight or more of a polyisocyanate or an isocyanate compound having a radically polymerizable unsaturated bond that is not a component of the polyester polyurethane (meth)acrylate (A-1) and (A-2).

2. In an adhesive resin composition excluding a diluent, The three components, polyester polyurethane (meth)acrylate (A-1), polyester polyurethane (meth)acrylate (A-2), and (meth)acrylate monomer (B), are blended in a total amount of 55% by weight or more. The active energy ray curable laminate adhesive resin composition according to claim 1.

3. (A-1) / (B) is 50 / 13 or less, The active energy ray curable laminate adhesive resin composition according to claim 1.

4. A compound comprising at least one of the following: epoxy resin (C), alkoxysilyl group-containing radical polymerizable compound (D), phosphate group-containing (meth)acrylate (E), and photocationic polymerization initiator (F), The amount of this compound is, relative to the active energy ray curable laminate adhesive resin composition excluding the diluent, In the epoxy resin (C) mentioned above, 1 to 10% by weight, In the alkoxysilyl group-containing radical polymerizable compound (D), the amount is 0.1 to 5% by weight. In the phosphate group-containing (meth)acrylate (E), 0.1 to 5% by weight, The photocationic polymerization initiator (F) is present in an amount of 0.1 to 5% by weight. Characterized by, The active energy ray curable laminate adhesive resin composition according to any one of claims 1 to 3.

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